1. Field of the Invention
The present invention relates to a moving body drive control device for controlling drive of a moving body, for example, such as a vehicular backdoor, so at to operate the moving body to be moved at a specified speed when driven by use of a motor.
2. Description of the Related Art
There has been proposed an operation technology of moving a moving body such as a vehicular backdoor and a slide door by use of a motor as a drive source to open/close the moving body automatically. In the case of opening/closing the backdoor, the slide door and the like as described above automatically, it is required that a moving speed thereof be controlled at a specified speed to perform an opening/closing operation thereof smoothly.
In the case of operating to move the moving body by use of the motor as a drive source, the moving speed of the moving body is changed in accordance with a degree of energization from a battery to the motor. Therefore, control for the moving speed of the moving body is usually carried out by performing pulse width modulation (PWM) for pulse signals used for the energization from the battery to the motor.
Incidentally, in such a case of operating to move a slide door of a vehicle parked on a slope, self-weight of the slide door as a moving body affects the moving operation more than when the vehicle is parked on the level ground. Therefore, even if a duty ratio of the pulse signals for the energization from the battery to the motor is controlled at the lowest level by the PWM control, the moving speed of the moving body exceeds a target speed in some cases. Moreover, in the backdoor opening/closing in the vertical direction of the vehicle, due to a structure thereof, a closing operation thereof is greatly affected by the self-weight of the backdoor, and an opening operation thereof is affected by biasing force from an biasing member such as a gas stay. Therefore, even if the duty ratio of the pulse signals for the energization from the battery to the motor is set at the lowest level by the PWM control, the moving speed of the moving body sometimes exceeds the target speed.
In consideration of the points as described above, for example, the gazette of Japanese Patent Laid-Open No. Hei 10(1998)-246061 proposes a technology of approximating the moving speed of the moving body to the target speed, in which the motor is set in a regenerative braking state to apply braking force to the moving body when the moving speed of the moving body cannot be lowered to the target speed only by the PWM control for the motor. In this case, when the braking force applied to the moving body becomes too large, the moving speed of the moving body is drastically lowered, and thus a smooth motion of the moving body will be hindered.
Accordingly, the gazette of Japanese Patent Laid-Open No. Hei 10(1998)-246061 proposes the control for the moving speed of the moving body, in which the regenerative braking state and a free state where the regenerative braking state is released are alternately set when the braking force is applied to the moving body by the regenerative brake of the motor, and thus the braking force applied to the moving body is adjusted not to be too large.